When a print system comprising a printer host and a printer carries out a printing process, an actual printing is executed by way of a plurality of processing stages. These stages may include the followings: a stage where print data is generated based on image data and the generated print data is stored as a spool file, a stage where the spool file is read out while a status of the printer is monitored and the spool file is outputted to the printer as print data, and a stage where the print data is interpreted so as to execute printing, and the like.
Processes in each stage are carried out mainly by hardware such as a CPU of the printer host, an output port of the printer host and a CPU of the printer.
Since a throughput of the hardware is different from each other, even when the processing time of one piece of hardware is quite high, the processing time as a whole system may be rendered low, if the processing time of another piece of hardware is low.
As a related art regarding the printing process time, Japanese Patent laid-open Publication No. 2002-248837 discloses that a printing time when ink of four colors, CMYK (Cyan, Magenta, Yellow, black) is used, and a printing time when ink of six colors, CMYKcm (Cyan, Magenta, Yellow, black, light cyan, light magenta) is used, are obtained, and in accordance with a user's desire, the printing time is shortened.
Japanese Patent laid-open Publications No. 2001-100970 and No. 2001-100969 disclose that a process time of a color conversion/half-tone processing and a transfer time to a printer are measured as to a part of RGB image data. Then, it is determined which of an RGB image data command and a CMYKcm binarized image data command completes a process in a shorter time. When the remaining RGB image data is printed, a switching operation is performed so that the time up to when a printer executes printing as to a drawing command can be shortened.
Japanese Patent laid-open Publication No. 2000-293327 discloses that a printing controller comprises at least a print managing section which generates print data for making a printer execute printing in a prescribed manner and a transfer control section which transfers the print data periodically to the printer while buffering the print data. The transfer control section detects a transfer rate of each cycle, dynamically changes the buffer size for print data of the next cycle in accordance with the transfer rate of the preceding cycle and suppresses the down time of the printer and the print data managing section. The print data items in the first cycle are buffered in a buffer size that is minimally necessary for the printer to start printing, and when the total value of the buffer sizes reaches a prescribed value, the buffer size for the print data of the subsequent cycles is made close to a maximum size in which the most efficient transfer can be performed. Then, it is possible to effectively utilize resources.